Dynamic polaronic screening for anomalous exciton spin relaxation in two-dimensional lead halide perovskites.

ABSTRACT: Two-dimensional lead halide perovskites with confined excitons have shown exciting potentials in optoelectronic applications. It is intriguing but unclear how the soft and polar lattice redefines excitons in layered perovskites. Here, we reveal the intrinsic exciton properties by investigating exciton spin dynamics, which provides a sensitive probe to exciton coulomb interactions. Compared to transition metal dichalcogenides with comparable exciton binding energy, we observe orders of magnitude smaller exciton-exciton interaction and, counterintuitively, longer exciton spin lifetime at higher temperature. The anomalous spin dynamics implies that excitons exist as exciton polarons with substantially weakened inter- and intra-excitonic interactions by dynamic polaronic screening. The combina

SUBMITTER: Tao W 

PROVIDER: S-EPMC7679171 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature